Weaving of knotted tuft fabric



Sept. 28, 1937. w. A. nice ET AL I 2,094,375

' WEAVING OF KNOTTED TlUFT'FABRIG Filed Jan. 31, 1933 4'Sheets-Sheet 1 Inventors l lizlter Elf ice ai 15 1 2102766 5114706, I

Sept; 28, A. RICE ET 2,094,375

WEAVING 0F KNOTTED TUFT FABR IC 4 Sheets-Sheet Filed Jan. 51, 1933 Spt. 2s, 1.937. w. A. RICE ET'A 2,094,375

WEAVING 0F KNOTTED TUFT FABRIC Filed Jan. 51, 1935 4 Sheets-Sheet," 3

' Patented Sept. 28, 1 937 PATENT or ies? WEAVING OF KNOTTED TUFT FABRIC Walter A. Rice, Yonkers, and FranklG. Shinn, Bronxville, N. Y.

Application January 31, 1933, Serial No. 654,469

Claims.

,Our invention relates to a method for weaving Persian-knot fabrics. A purpose is to adapt methods of oriental knot formation to use in modern weaving equipment 5 such, for example, as the Axminster type-of loom. A further purpose is to form a tuft yarn knot by combined movable tubes and movable grippers operating as close to the fell as possible. v A further purpose isto form the knots between thereed andthe fell while the reed is maintained continuously in the warp ready to beat up the knots and Weft threads.

A further purpose is to avoid failures in synchronism in knot-holding mechanism such as are likely to occur where a knot is transferred any considerable distance along warp threads.

A further purpose is to hold'one end ofthe tuft yarn" which indifferent forms may be the free end or the tube end-thereof, butpreferably both ends of the tuft yarn, substantially at the fell while the knot is being formed in close proximity to the retained end, producing a knot so close to the fell as to retain its tuft length during the beating operation.

2 A further purpose is to use .a yarn tube, or other device by which the yarn is manipulated which passes through crossed warp threads as the means ofadvancing the point of crossing of the Warp threads to a point close to the fell before the yarn is drawn off, thus facilitating the weaving of a w e, A

A further purpose is to space the warp threads uniformly at the reed, one thread to each space between reed dents and to pair the warp threads at the fell.

A further purpose is positively to hold the free end of the knot-forming yarn at the fell and to retain the other end in guides also at the fell during the final knot-forming operation and during beating up.

" 'A further purpose is to shift the free end of a tuft of pile yarn-from a position above the warp at a distance from the fell down through between 'cros'sed'warp threads at the rear of the crossing point, forwardly toward the fell and upwardly in T front of the crossing point andthere hold it While drawing out the yarn to form the knot, subsequently using a guide by which the yarn has been inserted to advance the position of the crossing to 50 a point close to the fell and, while it is so advanced, to bring the attached end of the yarn up substantially to the fell and then introduce a weft or binder prior to cutting.

further purpose is to utilize tubes and grippers' extending down under the crossed warp threads infront of and back of the crossing'point or vice versa, to pass a pile yarn under the crossing, subsequently withdrawing the tubes and grippers and to form the knot thus provided substantially at the fell, holding both ends of the knots'o 5 formed at the fell until after the knot hasbeeri beaten up and bound in by weft.

In the weaving of tufted fabrics a further purpose is to save loom time of transferring knots from the position at which they aremade tolthe 1Q fell by forming the knots substantially at the fell so that no transfer other than beating is required.

A further purpose is alternatively to form right or left hand Persian knots, determining the char acter of the knots by the selection and direction of 1 transfer of one or other of a pair of warp threads crossed over its mating thread of the pair. 7

A further purpose is to use combined tube and gripper mechanism on opposite sides oi a crossing point within a pair of warp threads as a means 20 of passing a tuft yarn from one end of the crossing to the other, preliminarily using the yarn tube or gripper initially carrying the tuft'yarn to effect crossing in the warp threads.

A further purpose is to move tuft yarn convey' ing tubes to position between pairs of laterally movable spring clamp fingers, and to then. withdraw the tubes from between the fingers,-leaving one end of the tuft yarn clamped therebetween'.

Further purposes will appear in the specificao0 tion and in the claims. I l

We have preferred to illustrate one main type with slight variations, selecting a type which is I practical and effective but'which has been se lected chiefly because of its value in illustration of the principles involved.

Figures 1, 3, 5 and 10 are diagrammatic plan views of loom parts used in carrying out our invention, the parts being positioned to represen parts of a cycle of weaving operation.

Figures 2, 4, 6, 7, 8, 9, 11 and 12 are diagrammatic vertical sections parallel to the lengths of the warp threads, showing successive positions in a cycle of loom operation. '01? these Figures 2, 4, 6 and 11 are taken upon lines 2-2,'4--4, fi li, and illl of Figures 1, 3, 5 and 10.

Figures 13 to '18 are diagrammatic fragmentary perspective sections illustrating steps in our process or method. r

Figures 19, 21, 23 and 28 are fragmentary dia- 9.

grammatic plan viewsshowing successive steps 5" in our method or process, crossing the, warp threads in a slightly different way from that in the preceding figures.

Figures 20; 22,- 24, 25, 26, 27, 29 and 3c are fragmentary diagrammatic vertical sections lengthwise of the warp threads further illustrating the several steps of our invention. Of these Figures 20, 22, 24 and 29 are sections upon lines 20-20, 2222, 24-24 and 2Q-26 of Figures 19, 21, 23 and 28 respectively.

Figures 31 and 33 are fragmentary vertical sections and Figures 32 and 34 are fragmentary side elevations of Figure 31 and Figure 33 respectively, illustrating gripper operation.

Figures 35 and 36 are perspectives showing sevarm of the positions of the previous figures, but reversing the tuft carrying members in the other figures.

Figures 37, 39, 41, 43, 45 and 4'? are fragmentary sections across the warp threads showing a plurality of warp thread pairs and the associated operating members and corresponding generally to sections taken upon single warp thread pairs at 37-42, 3939, ll-4i, 43-4-3, -55, 6?47, of Figures 38, 40, 42, 44, 46, 48 and 50 respectively.

Figures 38, 42, 44, 46, 48, and 50 are perspective views showing the various positions of the warp threads, tuft yarn, crossing comb, tuft yarn tube and gripper in the formation of a Persian knot.

Figures 49 and 50 show in section upon line 49-49 and in perspective a plurality of finished loops in loose formation and a single loop upon a single pair of warp threads respectively.

Figures 51 and 52 show in section similar to that of Figure 49 different arrangements of knots with respect to the warp threads from the arrangement shown in Figure 49.

In the drawings similar numerals indicate like parts.

This case is in part a continuation of our application for patent for Method and apparatus of weaving knotted fabrics, Serial No. 533,846, filed April 29, 1931, and is intended to cover the subject matter which in that case is specific to the use of two devices for manipulating a tuft yarn, one a yarn tube and the other a gripper, which meet below the warp threads of a pair and transfer the yarn from one to the other by which the yarn is passed as a loop under crossed Warp threads.

In the illustration the uncrossing of the warp threads transforms the loops thus made into knots. It is the intention to cover in the application to which reference is made above the broad subject matter applicable to the form of our invention shown in this case and to any other form or other forms shown in that application.

Our invention is directed to the machine pro; duction of knotted fabrics using the Persian knot, whether in rugs, carpets or tapestry. The. product is} intended. to correspond with the wellknown hand-formed Persian rug and tapestry products, and our process, and mechanism are, therefore, confined to the movements of elementswhich may be moved by hand-to facilitate tying of these knots, but which, for commercial operation, must be operated by machinery.

The fragmentary illustrations shown are capable of being hand-operated, but the advantage to be secured lies in the fact that these fragmentary showings are suitable for assembly as parts of a large machine operation which can be made up of a large number of like units in coincident operation.

In the various illustrations shown we have passed the free end of a tuft yarn between crossed warp threads in the rear of the crossing point of crossed warp threads to the front of the same'so as to emerge close to the fell, or have passed the tuft yarn in the opposite direction, drawing off the yarn to supply a knot, bringing the attached end of the yarn around also or retaining it close to the fell. The two ends of the yarn are brought substantially together at the fell and are held there taut while the weft or wefts are inserted and are beaten up, securing uniformity of the ends and avoiding slack yarn at the back of the fabric; The attached end is finally severed.

For convenience in dealing with the various forms, we will treat the devices by which the tuft yarns are manipulated as of two classes only, namely, tubes when the yarn passes through them, and grippers, where the yarn is firmly held by the device and the device is moved to manipulate the yarn by the movement thereof, whether these belong to the gripper class as ordinarily viewed by textile workers or to the needle class.

Where the tubes are intended to perform the additional function of laterally engaging alternate warp threads to cross them over intervening warp threads, the shed formation to facilitate: this purpose is preferably the first step.

In the illustration the warp threads initially lie in levelled position for the. beginning of a cycle of operation. A tuft yarn tube preferably of the Axminster type is positioned to enter the warp threads and pairs of clamping fingers comprising grippers are positioned to receive the tuft yarns from the tubes, one gripper for each tube.

In carrying out our invention we employ a plurality of warp threads arranged to. be operated. upon in pairs, and being here designated 55, 56, 55', 55', 55 55 etc. These threads pass from'a fell 5! (which preferably is fixed in position by the use of take-up mechanism, and may therefore correspond with a breast 58) back through the:- usual loom reed to heddles 59 and 60. Eachi thread passes through the eye of'one of the heddles so that shedding of the warp threads can be effected by them. The threads pass over the: usual tensioning devices to a source of warp: thread supply or beam (not shown) at the rear of the loom.

The usual shuttle 6! is carried by the shuttle frame 62 which is adapted to be shot back and forth across the lay by a conventional picker motion (not shown) in a manner common and Well known in the weaving art, in order to place one or more weft or filling threads. While we have herein illustrated a shuttle as the means for inserting the weft or filling, we desire it to be understood that we contemplate (alternatively) usingthe regulation Axminster needle for the same purpose, if desired, in which case a double Weft shot Will be placed after the formation of each row of loops or knots andbefore any change is made in the shed. l

The yarn intended for the formationof the yarn tufts is carried upon spools 63 which are rotatable within frames carried by an endless chain Bias is common in Axminster weaving. The tuft yarn is fed through tubes 65 which are integral with the frames, The frame units, come prising the frame; tubes and spool, are detachable one at a time from the endless chain for introduction to the knot forming mechanism. After an individual frame has been acted upon by the knot forming mechanism, it is returned to the endless carrier .chain, and the chain is moved to bring the next adjoining frame unit into registry with the transferring mechanism. From the time a frame unit is taken from. the chain until it is returned thereto and the chain is moved ters-es "to bring the next frame into register for a succeeding operation, constitutes a cycle which completes a row or shot of the weave.

The chain is carried by the usual sprocket 66 and the frame, when free from the chain, is handled by arms 61, one at each side, rock shaft 68 (pivoted in the frame at 69),an d rod 10.

. The arms 61 not only convey the frames from the chain and back to it but, with theassistance of allied mechanism, carry them through a cycle of knot forming operation.

. The frame and tube mechanism just described is generically old in the Axminster loom art, and

the general control of the movement is intended to be the same as in that art, i. e. by suitable cams,

etc., but the specific movements given and the suited to our processes and methods.

The yarn supplied from the spool is threaded through the tubes 65, and projects from the bottoms of the tubes to present free ends, H,- one to each pair of warp threads Withinthe loom.

Close to the fell we support a guiding comb of which two types are shown at 12 and 12' respectively, that shown at 12 being seen in Figures 1 to 18 and 12' being shown in the remaining figures.

The teeth I6 are guiding or spacing teeth, to draw together into pairs at the fell warp threads which are uniformly distributed at the reed, one warp thread to each space between reed dents, a

construction which is believed to be new to us,

whereas the comb 12 maintains at the fell a pairing of warpthreads which already exists in that two warp threads pass through each space.

The comb 12 or 12' is mounted upon arms 13 pivoted at a point not shown and is controlled in its movements by a rod 14 pivoted to the arms at 15; with the purpose and intent that the comb may be lifted into the position shown in Figure 2,

Normally oneof each of these pairs of warp" threads will coincide approximately with the slot positions and the other threads of the pairs will be engaged by intermediate parts of the sloping tooth surfaces and will be guided into the respective slots. This is for a purpose, the need of which is afterward more clearly shown, of providing wider spacing between the two' warp threads of each pair than the normal spacing between these warp threads, facilitating the passage between the warp threads of each pair of a device for manipulating a tuft yarn. 7

Since the spacing to be provided is between the two warp threads of the same pair it'will be clear that the warp threads fitting into any one ofthe slots'are not the warp threads of the same pair, but warp threads in different positions in adjoining pairs, that is, the adjoining warp threads of different but adjoining pairs. 1

Whether a comb be used or not,: and whether the comb of the first eighteen figuresbeused or not, it is the intention in the process or method claimed herein to cross the individual warp threads of each pair upon which the same knots are'to'be formed, one warp thread of the pair over its mating warp thread of the pair, in order that'on'e of thetwocrossings so formed can be used to assist in the formation ofthe Persian knoton this pair. I

As the initial step to the crossing when formed.

by the methods shown, we form a shedof .the

warp threads, which need not be a completeshed,

one thread from each pair being placed in the upper shed level, as seen at 55 in Figure 2, and. 'thef-others, one from each pair of warp threads less they have previously been placed in this positionso that when laterally moved they willengage'with the upper shed level warp threads 55 and carry these warpthreads with them.

The yarn manipulators, here tubes 65 are then shifted laterally to what, for purposes of description, may be considered an excessive distance, i. e. further than the distance at which they are intended ultimately to rest. This brings these yarn tubes laterally beyond the positions of the warpthreads 56, 56', 56 (Fig. 3) so that when these warp threads 56, are lifted, or when the F yarn tubes are further depressed, the lower ends ofthe yarn tubes will liebelow the levels of both setsof, warp threads and will laterally ease the warp'thre'ads 55, 55, 55 to engage the warp threads 56, 55, 56 'when the yarn tubes 65 are laterally moved in the opposite direction to their first movement," that'is, in retracting direction.

In Figures 3 and 4 the lateral positions of the tubes 65 are shown in Figure 3 and the height of the tube with respect to they heights of the warp threads 55 and 55 are shown. In this position of the parts the threads corresponding to 56 have not yet been shifted high enough to be engaged by the tube, nor has the tube been lowered far enough to engage the threads. The parts are therefore not yet in position for the tubes to be eased back toward their positions in Figure 1.

When the threads 56, 56, 56 have been lifted 'or the tubes'have been dipped further so as to provide forlateral engagement the tubes 65 are moved back to lateral position corresponding with their initial position in Figure 1. This results in easing the lateral displacement of the threads 55, 55', 55 and laterally displacing threads 56, 56', 56 in a direction reverse to that of the displacement of the threads 55, 55', 55 balancing the displacements of the threads, reducing the tensionupon threads 55, 55', 55 and releasing the tension upon these threads as compared with threads 56, 56' and 56 The result of the lateral displacement of threads 55, 55', 55 in one direction and 56, 56',

60 between the tubes and the lay. The crossings correspond to those shown in Figures 5 and 6 but the tubes are not in the same positions. as to distance from the fell as in Figures 3 and 4,

having swung toward the fell at the same time that they have dipped further between the warp threads.

The crossings 19 are used by us in the forma-' tion of our knots, while the crossings are, for

our purpose, accidental, idle and resultant crossings which are not used except as their presence with the tension in the warp threads makes ultimate withdrawal of the tuft yarn tube 65 from its position within the warp threads result in uncrossing the warp threads, changing the tuft yarns laid as U loops, each in a single plane parallel to the length of the warp threads, into Persian knots. I I

The devices formanipulatihg the tuft yarn, whether tubes as in Figures 1 to 34, or grippers as in Figures 35 and 36, areintended to cooperate with other tuft yarn manipulators, either grippers as in Figures 1 to 34, or tubes as in Figures 35 and 36, located upon opposite sides of the crossings 19 considered in a directionlongitudinal to the tuft yarns. This means that in Figures 1-34 one of each pair of grippers during operation passes a between the crossed warp In Figures 1 to 34 the tubes cooperate with grippers 8|, which, in Figures 1 and 2, are shown as passing through between-the warp threads of the individual pairs. Preferably these grippers will not be passed between the warp threads of individual pairs until after the comb 12 has been raised to divide the warp threads, because of the desirability of having extra Warp thread spacing for the grippers, but the grippers may pass between the warp threads, before or after crossing of the warp thread, to be in position to engage the projecting tuft yarn ends in proper sequence of operation. a

The use of grippers in weaving operations is old, and the several movements to be given to them are, therefore, well within the range of' the designer. For this reason it has not been considered necessary to illustrate operating mechanism for bodily movement of the grippers, nor for opening and closing them in proper order so as to have them engage the tuft yarn ends II.

It is desirable to have the knots as laid located as close to the fellas possible in order that there may be as little disarrangement of the knots as permissible during the operation of beating up the knots against the fell, whether the knots be beaten up separately or in conjunction with the beating up of weft yarns, separating the successive rows of knots.

'We provide progressive transfer of the knot positions toward the fell during the operation of laying the knots by progressive shifting of the crossing points of the warp threads of the pairs toward the fell during the knotting operation.

- This is effected by bodily movement of that tuft it be tube or gripper, toward the fell during the successive operations performed by it. The fact of progressive bodily movement will be apparent from the successive positions of the tubes 65 toward the fell, seen in the several'positions of Figures 2, 4, 6, 8, 9, l1 and 12.

After the crossing of the warp threads has been effected, asdescribed, the manipulatingdevices farther from the fell, here" tubes 65, swing about the axis 69 and at the same time move bodily toward the fell, carrying the tuft yarns with them fro-m the positions in Figures 6 and 15 to the positions shown in Figures 8 and 16, where the tuft yarn grippers Bl, are open to receive the tuft yarn and do'engage and hold the proje'cting tuft yarn ends H, after which the ends H are withdrawn'by upward movement of the grippers 8|, preferably in a general direction of their lengths with bodily movementtoward the fell, bringing them initially'to some such position as seen in Figure 9. They, are held prefer ably at or'near the position shown in Figure -9. The exact relation between theftime of their movement to this position and the time of movewardly as the tuft yarn gripper 8| is moved upwardly; with the qualification, however, that the gripper 8 I shouldpreferably pull out of the tube 65 a sufficient'length of tuft yarn to provide for a full movement ofgri'pper 8 in making the'knot before the tuft yarn tube .65, leaves thewarp threads, in order that the part of the tuft yarn forming the body of the knot need not be subsequently pulled through. As the tube is lifted it will expose the tuft yarn endlwith little or no,

physical movement'of this end during the tube the attached portion'of the tuft yarn being'held by its connection through the tuft yarn tube with the spool-where. any desired'braking can be had.

In the position of Figure 11 the tuft yarngripper 8| can be located high enough to permit cutting ofwhat has been called the free end H by the knife 82 or the exact positioning of the free ends of the tuft yarn may be relied upon to give them proper length Without cutting. In either event the attached end of the tuft yarn is cut by the knife in the positionof Figure 12.

The perspectives of Figures 13 to 18 show various steps. ,The divided but un'crossed warp threads are shown in Figure 13 with the two threads in the same slot from different pairs. In t Figure 14 the upper warp threads have been- V crossed over the lower warp threads far enough for the tubes to have passed laterally beyond the lower warp threads with which the respective warp threads are to be paired. In Figure 15 the tubes have come back to position for symmetrical crossing of the warp threads.

' In Figure 17 the warp threads have been crossed in the opposite direction,'that is, the warp threads which form the lower position in the shedding of'Figure 14 are in the upper positionin Figure '17, with the. result that the crossing must be effected by movement of the tubes in the opposite lateral direction from the'initial movement of the tubes in Figure 14. For this I reason instead of producing 'right-handed'knots shown in Figures 4'7, 49 and 52, as in the operation including-the movement of Figure 14, leftin Figure 1'7. The formation of right and left knots may be alternated, weaving first right knots and then left knots in alternation.

Whichever the type of knot initially planned and produced'the knotting does not become effective in these figures until release of the divertedwarp threads by removal of the tube from its position between them.

In Figures 19 to 30 and 37 to 50 the comb 72 at the fell differs from the comb in the earlier figures in that the comb slots Tl correspond in number and spacing with the number and normal spacing of the warp threads. Since two warp threads pass through each space between adjoining reed dents, the warp threads here are already pairs. In this case also the pairing is different from the pairing ultimately effected by the knots common to both warp threads of the final pairs. They are intended to hold two warp threads each and to maintain the spacing of the warp threadsduring the several operations up tothe time when the knots are ready to be beaten up. The chief advantage of the use of this comb lies in preventing the warp threads within the individual pairs from being displaced toward each other during the crossing of the warp threads and while they are crossed, thus maintaining better spacing than would otherwise be provided for the grippers 8| in their passage between the warp threads. Even if the grippers 81 be passed through the spaces between the pairs of warp threads before the crossing takes place the comb maintains warp thread spacing and thus renders the operation more trustworthy and reliable than in the absence of the comb; and where it is desired to insert the grippers after the crossing, crowding at the fell of the individual warp threads of the pairs to be knotted together is pre vented.

In Figures 19 to 30 the crossing of the warp threads is effected by movement of the lower warp threads of the pair in the shedding shown. With the same shedding this will, of course, mean that the lower warp threads must be moved in a direction opposite 'to the direction of the movementv of the upper warp threads in order to effect the crossing and that the same. kind of knots will be produced, namely, right-hand knots if right-hand knots would be produced by crossing the upper threads and vice 'versa. To produce opposite knots, as compared with those produced by shifting the upper warp threads of the pairs the shedding must be reversed to place in the lower shed level thosewarp threads of the pairs which otherwise would appear in the upper shed level.

The crossing operations are illustrated in Figures 19 to 24 and 39 to 42 in which after the shedding the threads of the lower shed level are engaged by pins 83 upon bars 84 which may be shifted vertically to bring the pins within the warp threads, or about which the warp threads may be shifted downwardly to bring them in line with the pins. V

In either event the warp threads are shifted laterally'from thepositions seen in Figures 19 and 20 to the positions seen in Figures 21 and 22. In the latter positions the warp threads have been shifted toward the lower part of the sheet to an excessivee'xtent; They then lie beyond the coinplementary warp threads of the several pairs so that Withjurther upward shifting of the pins or with downward shifting of the upperwarp threads the complementary warp threads of the pair will be, in position laterally to be engaged by the pins.

Reverse lateral shifting of the pins will now di-v vert the complementary warp threads of the pairs to an extent seen in Figure 23 and at the same time will slightly release from their lateral tension, those warp threads which were initially shifted,

to secure the shifting of the warp threads to cooperate with other features of our invention, such, for example, as with the use of the tuft yarn tubes or grippers to force the crossing point up toward the fell. This cooperates well with the crossings shown but will cooperate also with a crossing in the warp threads however formed.

Instead of effecting the shifting of the warp threads by the tuft yarn tubes, as in Figures 1 to 18, and by this means placing the tuft yarn tubes between the warp threads as part of the warp thread shifting operation, the tuft yarn carriers in later numbered figures are passed between the warp threads after the warp threads have been crossed, that is, between the positions of Figures 22 and 24.

From the positions of Figures 23 and 24 at which the tuft yarn carriers lie within the warp threads the operation shown in Figures 19 to 50 is substantially the same as that intended to be shown in Figures 1 to 18, but with the difference that the pins 83 and bars 84, though no longer needed after the crossing of the warp threads are to be reckoned with to the extent that they must be kept out of the way of the operating parts, which means both that they must not interfere with positioning the tubes 65 nor with the subsequent movement of these tubes, and that they must be kept out of the way of the lay in the subsequent placing of the weft thread and beating up of the tuft yarn knots and of the weft thread, whether they be beaten up separately or together.

In Figures 19 and 20, 37 and 38 the parts are in position for the beginning of the cycle except that the comb 12 is in position within the warp threads, the grippers have been passed between the warp threads of the individual pairs and the pins 83 in Figs. 19 and 20 have been placed within the lower warp thread range for shedding of the warp threads. In Figures 38, 40, 42, 44, 46,, 48' and 50 the disclosure of a single pair only results in showing but one warp thread to each comb whereas with this form of comb it is intended to gather together within each comb slot two warp threads, one each from adjoining warp thread pairs as seen in Figures 13 to 15 and 17.

In Figures 21 and 22, 39 and 40, the first (relatively excessive) lateral shift of the warp threads by the pins has taken place and in Figures 23 and 24 the pins have engaged with the other (complementary) warp threads of the pairs, shifting them laterally and permitting the first warp threads engaged to move back to a position of symmetry in crossing, the warp threads having been brought to a common level and the tubes havingbeen dipped beneath the common shed level and between the crossed warp threads upon the side ofthe crossings of these warp threads away from the fell.

.In Figure 25 the tubes have progressively moved bodily in clockwise direction in the figures from the position of Figure 24 to the position of Figure 25, Carrying the tuft yarn and forcing crossing toward the fell, until they have reached a point wherethe previously opened gripper fingers 85 and 225 engage opposite sides of the tubes at the pers are preferably gradual and'progressive and as far as possible take place concurrently, in order to save weaving time, it is not essential'from the theory of the operation that the movements shall be concurrent. Whether this be true or not the next step is in the withdrawal of sufficient lengths of tuft yarn from the respective tubes for the knot formation. This preferably takes place for the most part during the movement of the grippers from the positions shown in Figures 26 and 44to the positions shown in Figures 27 and 46 and before the tuft yarn carrying tubes are withdrawn from their positions between the crossed warp threads of the respective pairs on the sides of the crossing away from the fell. Some of the tuft yarn within the tube will be exposed, of course, (to form one tuft end of the knot) as the tube is further lifted. The purpose of this is to place the tuft yarn lengths thus drawn out, in proper position around under from one side to the other, (here back to front or front to back), of the crossing in the position close to the fell.

1 Whether the entire lengths of tuft yarn be withdrawn before the tubes emerge from the warp thread shed or not the pins 83 are preferably withdrawn from their positions between the warp threads of the respective pairs before those carriers locatedback of the crossings are lifted out of the warp threads, resulting in immediate straightening (uncrossing) of the warp threads of the respective pairs as soon as the tuft ure's 27-30 and in Figures 46 and 48, it will be' seen that the tubes preferably progressively advance bodilyto-ward the fell during this latter part of the operation also, additionally advancing the tuft yarn knots toward the fell and reducing the distance through which these tuft yarn loops need to be driven when they are beaten up. For convenience in placing the grippers between the threads of adjoining pairs of warp threads with a minimum of spacing the warp thread fingers '85, 88 for different tuft yarn tubes may be placed in different levels initially as seen in Figures 31 to 33. Though a breast plate is shown mounted to swing about an axis 88 and held by spring 89 against a stop 90 it will be evident that this is not crossing of the warp threads.

essential and that if used its detail-as in the case of the detail of the other structure shown-' need not be followed;

Our processes and methods facilitate the formation of an extremely low pile without shearing, thereby avoiding'waste of the more costly yarn comprising the pile product. They also permit of pile formation of varying pile lengths while still retaining all of the advantages of forming the knots close to the fell. This shortness of knot movement combined with the holding of both ends of the tuft yarn during the loop or knot formation, maintain the initial tight contacts of the tuft yarn of the knots with the warp threads, and at the same time secure uniform height for both tufts. Variation in the character of the tuft yarn tubes or grippers, in the direction of their movement and in the cooperation with other mechanism may take place Without losing these advantages. f

The final movements of the frame and tubes from the position of Figures 9 and 27 are preferably upward and forward but obviously the movements of rotation and the vertical movements of the tubes can be combined to form composite paths of movement, preferably to a position shown in Figure 11 or 12, in which, or in some similar position, the tubes are held stationary in their travel while a second shed is formed in the warp threads, and one or more shots of weft yarn are put in and beaten up. It is not intended here to indicate that the beating up of the knots must wait for the placing of the Weft but ordinarily this will be the case.

The accurate predetermination of the lengths height of the pile while weaving a very low pi1e fabric.

It will be evident that in the, reversal of parts illustrated in Figures 35 and 36 where the tuft yarn guide is at the fell and the grippers enter through the .rear of the crossing, the tuft yarn guide 68 can be inserted between the warp threads of the pair either before or after the The warp threads need not be crossed in one particularway. The gripper BI is usedtoeffect the movement of the crossingtoward the fell and any relation of movement between the tuft.yarn guide and gripper can be usedwhich may be desired to insure'p'ulling the proper amount. of tuft yarn from the guide which may be desired-eand no more-- by concurrent 'or separate movements of these parts.

' It will be evident that whatever the number of weft threads 9| laid after each course of tuft yarn knots, the knots and the'weft yarn can ,be

beaten up separately if desired, or concurrently at the wish of the designer. e

It is not the intention of this application to stressspecial relations of weft threads to the knots or warp threads, but to indicate instead that ourinvention is suitable for use with a considerable variety of Weft thread. introduction, placing the weft threads after the knots have been formed with any suitable shedding of the warp threads and in any quantity of weftthreads in one placing which may be desired singly, as with a 'shuttle,double, as with a shuttle or with a needle'or in any multiples of either that may be dictated bythe character of ultimate weft which is desired. Y s I It will be evident that all of our work is done without interference from the reeds, whose dents remain in the warp threads at all times. Our methods and apparatus do not require deviation of the Warp threads from their normal horizontal position except as the warp threads must be formed in sheds and must be crossed.

It will be evident that the method and mechanism applying the tapered comb teeth of Figures 1 to 18 and the single warp threads per space between the dents facilitates a finer weave than in the method and structure of the other figures.

This condition permits application of our invention to normal looms with normal loom operating mechanisms contemplating a minimum of change. The changes required are rather changes of addition than of alteration.

It will be evident that the same methods which apply to the formation of right-hand Persian knots 92, as seen in Figures 47 to 50, are applicable also to the formation of left-hand Persian knots, such as are seen in Figure 51, and that the rows of knots can be alternated one row right-hand and the other row left-hand by the simple expedient of reversing the shedding, and either reversing the direction of crossing or shedding by movement in the upper shed level where the lower shed level had previously been used or vice versa.

In view of our invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain part or all of the benefits of our invention without copying the structure shown, and we, therefore, claim all such in so far as they fall within the reasonable spirit and scope of our invention.

Having thus described our invention, what wev claim as new and desire to secure by Letters Patent is: v g Y 1. The method of weaving a rug in a loom having warp threads in pairs, means for shedding the Warp threads, and yarn tubes and grippers, which consists in partly shedding the warp threads with the two threads of each warp thread pair in different shed levels, in crossing one warp thread over the other within each of the pairs by lateral movement of the yarn tube, in dipping the yarn tubes used to effect the crossings further between the warp threads, in passing the grippers down between the warp threads on the fell side of the crossings, in transferring the ends of the tuft yarn from the yarn tubes to the grippers beneath the warp threads and in removing both the yarn tubes and grippers from beneath the warp threads and concurrently uncrossing the warp threads.

2. The method of weaving a rug in a loom having warp threads in pairs, means for shedding the warp threads and tuft yarn tubes and grippers, which consists in partly shedding the warp threads with the two threads of each warp thread pair in different shed levels, in crossing the warp threads within each of the pairs by lateral move- ,ment of the tubes, in dipping the yarn tubes used to effect the crossings further between the warp threads on one side each of the corresponding warp thread pair crossings, in passing the been effected are still in the warp threads, in

uncrossing the warp thread pairs by removal of the yarn tubes while maintaining the hold upon one end each of the tuft yarns and in beating up the knots so formed while maintaining the hold upon the tuft yarns.

3. In the operation of tying Persian knots about warp threads in a loom using warp threads, weft threads, wires and two sets of movable tuft yarn manipulators, one set comprising tubes and the other set adapted to withdraw tuft yarn from the tubes, the novelty which consists in shedding the warp threads with threads of individual pairs in different shed levels, in using one set of manipulators to shift one thread of each pair laterally beyond the other thread of each pair to cross the warp threads, in withdrawingthe tuft yarns from the tubes by the manipulators at points beneath the warp threads and pulling them up between the warp threads on opposite sides of the crossings all while maintaining the wires in the warp threads, in inserting weft and in beating up the weft and the tuft yarn inserted.

4. In a loom for weaving knotted fabric, warp crossing mechanism and a comb having a tooth for each pair of warp threads, each tooth being high at a point located between the warp threads of its pair, having a slot immediately adjoining this high point on one side and a slope on the other leading to the slot adjoining the high point of the next tooth whereby the warp threads of an individual pair are separated by the sloping part of the tooth and the adjoining threads of different but adjoining pairs of warp threads are collected together in the slots.

5. In the operation of tying Persian knots about warp threads in a loom using warp threads, weft threads, wires and two sets of movable tuft yarn manipulators, one set comprising tubes and the other set adapted to withdraw tuft yarn from the tubes, the novelty which consists in shedding the warp threads with threads of individual pairs in different shedlevels, in using one set of manipulators to shift one thread of each pair laterally beyond the other thread of each pair to cross the warp threads, in withdrawing the tuft yarns from the tubes by the manipulators at points beneath the warp threads and pulling them up between the warp threads on opposite sides of the crossings at the same side of the warp, all While maintaining the wires in the warp threads, in inserting weft and in beating up the weft and the tuft yarn inserted.

WALTER A. RICE. FRANK G. SI-IINN. 

